Ten years ago, psychologist Sue Palmer predicted the toxic effects of social media. Now she sees a worrying new danger…

When the little girl pointed at the sweets at the checkout, her mother said: ‘No, they’re bad for your teeth.’ So her daughter, who was no more than two, did what small children often do at such times. She threw a tantrum.

What happened next horrified me. The embarrassed mother found her iPad in her bag and thrust it into her daughter’s hands. Peace was restored immediately.

This incident, which happened three years ago, was the first time I saw a tablet computer used as a pacifier. It certainly wasn’t the last. Since then, I’ve seen many tiny children barely able to toddle yet expertly swiping an iPad – not to mention countless teenagers, smartphone in hand, lost to the real world as they tap out texts.

It’s ten years since the publication of my book, Toxic Childhood, which warned of the dangers of too much screen-time on young people’s physical and mental health. My fears have been realised. Though I was one of the first to foresee how insidiously technology would penetrate youngsters’ lives, even I’ve been stunned at how quickly even the tiniest have become slaves to screens – and how utterly older ones are defined by their virtual personas.

Indeed, when my book came out, Facebook had just hit our shores and we were more concerned with violent video games and children watching too much TV. Seems like ancient history, doesn’t it? Today, on average, children spend five to six hours a day staring at screens. And they’re often on two or more screens at once – for example, watching TV while playing on an iPad.

Because technology moves so fast, and children have embraced it so quickly, it’s been difficult for parents to control it. And when it comes to spending a childhood in front of a screen, this generation are like lab rats. The long-term impact is not known.

Even before iPads hit the market in 2010, experts were warning that 80 per cent of children arrived at school with poor co-ordination, due to a sedentary lifestyle.

Along with colleagues in the field of child development, I’d seen a rise in prescriptions for Ritalin, a drug for attention deficit and hyperactivity – a four-fold increase in less than a decade. And we’d collected a mass of research showing links between excessive screen-time and obesity, sleep disorders, aggression, poor social skills, depression and academic under-achievement.

It’s little wonder, then, that the boom in iPads and smartphones has coincided with further deterioration in the physical and mental health of children of all ages. Sadly, we’re seeing the rise of the ‘techno-tot’ for whom iPads have become the modern-day equivalent of a comfort blanket.

Recent research found 10 per cent of children under four are put to bed with a tablet computer to play with as they fall asleep. One study of families owning them found a third of children under three had their own tablets. Baby shops even sell ‘apptivity seats’ into which a tablet can be slotted to keep toddlers entertained.

Few know that the late Apple boss Steve Jobs didn’t let his own children have iPads. I wish he had gone public on this as other parents might have followed suit.

Because the earlier children are hooked on screens, the more difficult it is to wean them off.

This is not the only worry. It’s not just what children get up to onscreen that affects their overall development. It’s what screens displace – all the activities they’re not doing in the real world. Today’s children have far fewer opportunities for what I call ‘real play’. They are no longer learning through first-hand experiences how to be human and are much less likely to play or socialize outdoors or with others.

One of the most depressing examples of a totally screen-based childhood involved a ten-year-old in London. The overweight, pasty-faced little lad told me: ‘I sit in my room and I watch my telly and play on my computer . . . and if I get hungry I text down to my mum and she brings me up a pizza.’ The change in children’s play has happened in little more than a couple of decades. While many parents feel uneasy about all that screen-time, they haven’t tackled it as they’ve been so busy keeping up with changes in their own lives.